Levels of beta-HCH, HCB, p,p'-DDE, p,p'-DDT and PCBs in human milk from a continental town in Croatia, Yugoslavia.

Concentrations of beta-HCH, HCB, p,p'-DDE, p,p'-DDT and PCBs were determined by gas chromatography in 50 human milk samples collected from the general population during 1981/1982 in a continental town in Croatia (Yugoslavia). The samples were collected between one and 22 weeks after delivery from mothers breast-feeding one child only. The mothers' age was 18 to 31 years, and they were nursing their first or second child. All 50 samples contained beta-HCH, HCB, p,p'-DDE and PCBs, whereas p,p'-DDT was present in 37 samples. The concentrations of beta-HCH, HCB, p,p'-DDE, p,p'-DDT and PCBs expressed on a whole milk basis were (median in microgram/kg): 11, 7.1, 67, 7.3 and 22 respectively, and expressed on a fat basis (median in mg/kg): 0.28, 0.21, 1.9, 0.18 and 0.62 respectively. The fat content was 3.7% (median). PCBs were present in a mixture containing penta-, hexa- and heptachlorobiphenyls.

Occupational exposure control by simultaneous determination of N-methylcarbamates and organophosphorus pesticide residues in human urine.

On-column transesterification with methanol was applied for the gas chromatographic determination of N-methylcarbamates extracted from human urine. Transesterification conversion efficiencies of N-methylcarbamates dioxacarb, carbofuran and OMS-22, calculated from the amount of the on-column produced O-methyl-N-methylcarbamate (DMC), were 96, 77 and 76% with detection limits of 8, 10 and 10 ng, respectively. In the investigated concentration range of 0.2-3 micrograms/ml of urine the extraction efficiencies with methylene chloride were independent of the initial concentration of N-methylcarbamate added to urine samples of non-exposed persons. The recoveries and rel. S.D. were 74 +/- 11, 64 +/- 8 and 79 +/- 12% for dioxacarb, carbofuran and OMS-22, respectively. The procedure was applied for the gas chromatographic determination of carbofuran and its metabolites containing the N-methylcarbamic group extracted from urine samples of occupationally exposed persons in a pesticide formulating plant. The level of extracted N-methylcarbamates and the concentration of degradation products of organophosphorus pesticides detected in the urine of the same persons were correlated with the blood and plasma cholinesterase activities. Although the determination of DMC includes only a smaller part of the excreted N-methylcarbamate, a simultaneous determination of both carbamates and organophosphorus residues made it possible to distinguish the cause of depression in cholinesterase activity, indicating early and specifically the exposure to a particular group of agents hazardous to health.

DDT residues in samples of human milk, and in mothers' and cord blood serum, in a continental town in Croatia (Yugoslavia).

Concentrations of p,p'-DDE, p,p'-DDD, and p,p'-DDT were determined in 34 samples of human milk obtained 3-5 days after delivery and in 37 samples obtained at later times of lactation (up to 55 weeks). All samples contained p,p'-DDE, but only several contained p,p'-DDD and p,p'-DDT. The concentrations of p,p'-DDE were 31 microgram/l in the beginning of lactation and 53 microgram/l at later time intervals. The concentration ranges in both groups overlap almost completely and the difference in the mean values is not significant. Serum samples from 35 mothers and cord blood were also analyzed. All samples contained p,p'-DDE, the concentrations being 18 microgram/l and 6.8 microgram/l in the mothers' and cord blood serum, respectively. Serum samples of 24 non-pregnant women contained the same amount of p,p'-DDE (20 microgram/l) as mothers' sera. All samples were collected in a continental town of Croatia (Yugoslavia) between 1977 and 1979. The concentrations of DDT residues were determined by gas chromatography, and two methods for extraction from milk were used and compared.

The rate of urinary excretion of phosalone residues in occupationally exposed persons.

The absorption of malathion and phosalone was followed in occupationally exposed workers by determination of residues excreted in the urine. Because of the high concentrations found in the morning urine samples, the rates of excretion of phosalone metabolites in the urine of a volunteer experimentally exposed to phosalone during one and then again during three subsequent working days were investigated. The urinary excretion of phosalone metabolites was most intense 4--5 hours after exposure. At the beginning of the next day, the metabolites were still well measureable in the urine. Blood and plasma cholinesterase activities were only slightly reduced during exposure. The analyses of 24-hour urine samples, or of urine samples taken 4--5 hours after exposure, are not suitable for the routine control of occupationally exposed persons because of sampling difficulties. Instead, analyses of samples taken immediately before and after work hours have to be performed. A systematic increase in the concentrations of pesticide residues in the morning urine should initiate more efficient and well-timed protection measures.